Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene g...Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.展开更多
1.Objective The Emeishan basalts is located in southwest China and northern Vietnam,covering an area of 2.5×10^(5) km^(2)(Zhong YT et al.,2014),which is the first widely recognized large igneous province(LIP)in C...1.Objective The Emeishan basalts is located in southwest China and northern Vietnam,covering an area of 2.5×10^(5) km^(2)(Zhong YT et al.,2014),which is the first widely recognized large igneous province(LIP)in China(Zhang ZS,2009).The Emeishan LIP has attracted a numbers of scholars for the reason that the LIP may play a significant role in the evolution of environment and climate.Yang JH et al.,(2018)pointed out that the weathering of the Emeishan basalts consumed carbon dioxide and caused a decrease in the climate of the early Wuchiapingian.However,the duration and termination of the Emeishan basalts eruption remain in doubt.This paper reports a new discovery of tuffaceous in the middle part of the Upper Permian Wujiaping Formation from the northern margin of the Sichuan Basin,applying of LA-ICP-MS to obtain zircon U-Pb ages of tuffaceous and to constrain the lasted eruption timing of Emeishan LIP.展开更多
Background: Termination of pregnancy (TOP) in Zambia is guided by the Termination of Pregnancy (TOP) Act of 1972 and as amended in 1994 of the laws of Zambia. However, despite provision of Comprehensive abortion care ...Background: Termination of pregnancy (TOP) in Zambia is guided by the Termination of Pregnancy (TOP) Act of 1972 and as amended in 1994 of the laws of Zambia. However, despite provision of Comprehensive abortion care services with the liberal law, statistics at Kanyama First Level Hospital in relation to unsafe illegal abortions are alarming. This study sought to understand the Awareness on the TOP Act of the laws of Zambia among women of reproductive age 15 - 49 years at Kanyama First Level Hospital in Lusaka District. Purpose of the Study: To assess awareness on the TOP Act among women of reproductive age at Kanyama First Level Hospital in Lusaka, Zambia. Methodology: A convergent parallel mixed method design was conducted using both survey and in-depth interviews among women of reproductive age at Kanyama First Level Hospital in Lusaka District. The study surveyed 370 randomly sampled women aged 15 to 49 years old while the in-depth interviews included eight women purposively sampled from the survey population. Survey data was analyzed using descriptive and inferential statistics while qualitative data thematic analysis was used. Results: The study found that 37% of the participants were aware of the TOP Act while 63.8% viewed legalization of abortion for any reason as wrong. The study results also showed that widowed women were 8 times more likely to be aware of the TOP Act compared to single women (AOR: 8.262;95% CI: 1.105, 61.778). Women in business were significantly more likely to be aware of the TOP Act compared to those who reported having no occupation. (AOR: 2.61;95% CI: 1.246, 5.499). Limited access to information, the social stigma attached to abortion, health care providers’ attitudes, cultural norms, values and religious beliefs, restrictive legal requirements, and absence of a supportive network were some of the barriers affecting awareness and utilization of available safe abortion care services. Conclusions: The research findings concluded that a significant lack of awareness among women of reproductive age regarding the Termination of Pregnancy (TOP) Act. The majority of respondents held the view that abortion should only be legalized for medical reasons. Furthermore, there was a notable gap in knowledge concerning the penal code’s provisions on abortion.展开更多
The present study, carried out in the forest (Daloa) and pre-forest (M’Bahiakro) zones of Cote d’Ivoire, aims to determine soil landscape units using the coding method. Geological maps and satellite images (SRTM and...The present study, carried out in the forest (Daloa) and pre-forest (M’Bahiakro) zones of Cote d’Ivoire, aims to determine soil landscape units using the coding method. Geological maps and satellite images (SRTM and Landsat) were used for this purpose. The methodological approach adopted consisted in producing maps of slope, geology, land use and topography using the codification method. These various maps, integrated into a GIS using the coding aggregation method, were used to generate soil landscape maps. Twenty-seven (27) soil landscapes have been identified for the pre-forest zone (M’Bahiakro), with a strong dominance of acid rock over a moderate relief under savannah, forest/degraded forest and crops/fallow. However, the forest zone (Daloa), with forty-one (41) soil landscapes identified over the entire zone, is characterized by a majority of mafic rocks on a medium altitude under forest/degraded forest, water and crops/fallow. The criteria used from the codification method (sum of aggregations) made it possible to predict the spatial distribution of soil map units according to agro-ecological environments in the humid intertropical zone. This is essential for the orientation and reinforcement of soil survey tools. However, a comparative evaluation of the different multicriteria analysis methods for coding and weighting soil landscape unit mapping would enable us to identify the most suitable and efficient method for drawing up base maps for soil surveys.展开更多
Background:Acute suppurative terminal cholangitis(ASTC)is rarer than acute obstructive cholangitis and is not well studied.To explore this subtype of acute cholangitis,we described our clinical experience with ASTC.Me...Background:Acute suppurative terminal cholangitis(ASTC)is rarer than acute obstructive cholangitis and is not well studied.To explore this subtype of acute cholangitis,we described our clinical experience with ASTC.Methods:We performed a retrospective review of patients with ASTC admitted to our center from September 2014 to August 2020.We analyzed their clinical characteristics,including etiology,clinical manifestations,imaging features,treatment and prognosis.Results:A total of 32 ASTC patients were included in the analysis.The majority of the patients had a history of biliary operations,and clinical manifestations were occult and atypical.The positive rate of bacterial culture was 46.9%.All the patients had typical imaging features on computed tomography and magnetic resonance imaging.Treatment with effective antibiotics was provided as soon as diagnosis was established.After treatment,most patients had a good outcome.Elevated levels of total bilirubin,aspartate aminotransferase,procalcitonin and gamma-glutamyltransferase were the characteristics of critically ill patients and were associated with relatively poor prognosis.Conclusions:Our results demonstrated that ASTC should be recognized as a new subtype of acute cholangitis,and that earlier diagnosis and more personalized treatments are needed.展开更多
Machine learning(ML) is well suited for the prediction of high-complexity,high-dimensional problems such as those encountered in terminal ballistics.We evaluate the performance of four popular ML-based regression mode...Machine learning(ML) is well suited for the prediction of high-complexity,high-dimensional problems such as those encountered in terminal ballistics.We evaluate the performance of four popular ML-based regression models,extreme gradient boosting(XGBoost),artificial neural network(ANN),support vector regression(SVR),and Gaussian process regression(GP),on two common terminal ballistics’ problems:(a)predicting the V50ballistic limit of monolithic metallic armour impacted by small and medium calibre projectiles and fragments,and(b) predicting the depth to which a projectile will penetrate a target of semi-infinite thickness.To achieve this we utilise two datasets,each consisting of approximately 1000samples,collated from public release sources.We demonstrate that all four model types provide similarly excellent agreement when interpolating within the training data and diverge when extrapolating outside this range.Although extrapolation is not advisable for ML-based regression models,for applications such as lethality/survivability analysis,such capability is required.To circumvent this,we implement expert knowledge and physics-based models via enforced monotonicity,as a Gaussian prior mean,and through a modified loss function.The physics-informed models demonstrate improved performance over both classical physics-based models and the basic ML regression models,providing an ability to accurately fit experimental data when it is available and then revert to the physics-based model when not.The resulting models demonstrate high levels of predictive accuracy over a very wide range of projectile types,target materials and thicknesses,and impact conditions significantly more diverse than that achievable from any existing analytical approach.Compared with numerical analysis tools such as finite element solvers the ML models run orders of magnitude faster.We provide some general guidelines throughout for the development,application,and reporting of ML models in terminal ballistics problems.展开更多
In this work, the field plate termination is studied for Ga2O3Schottky barrier diodes(SBDs) by simulation. The influence of field plate overlap, dielectric material and thickness on the termination electric field dist...In this work, the field plate termination is studied for Ga2O3Schottky barrier diodes(SBDs) by simulation. The influence of field plate overlap, dielectric material and thickness on the termination electric field distribution are demonstrated.It is found that the optimal thickness increases with reverse bias increasing for all the three dielectrics of SiO2, Al2O3, and HfO2. As the thickness increases, the maximum electric field intensity decreases in SiO2and Al2O3, but increases in HfO2.Furthermore, it is found that SiO2and HfO2are suitable for the 600 V rate Ga2O3SBD, and Al2O3is suitable for both600 V and 1200 V rate Ga2O3SBD. In addition, the comparison of Ga2O3SBDs between the SiC and GaN counterpart reveals that for Ga2O3, the breakdown voltage bottleneck is the dielectric. While, for SiC and GaN, the bottleneck is mainly the semiconductor itself.展开更多
The point-contact high-purity germanium detector(HPGe)has the advantages of low background,low energy threshold,and high energy resolution and can be applied in the detection of rare-event physics.However,the performa...The point-contact high-purity germanium detector(HPGe)has the advantages of low background,low energy threshold,and high energy resolution and can be applied in the detection of rare-event physics.However,the performance of HPGe must be further improved to achieve superior energy resolution,low noise,and long-term reliability.In this study,we combine computational simulations and experimental comparisons to deeply understand the passivation mechanism of Ge.The surface passivation effect is calculated and inferred from the band structure and density of interface states,and further con-firmed by the minority carrier lifetime.The first-principles method based on the density functional theory was adopted to systematically study the lattice structure,band structure,and density of state(DOS)of four different systems:Ge–H,Ge–Ge-NH 2,Ge-OH,and Ge-SiO_(x).The electronic char-acteristics of the Ge(100)unit cell with different passi-vation groups and Si/O atomic ratios were compared.This shows that H,N,and O atoms can effectively reduce the surface DOS of the Ge atoms.The passivation effect of the SiO_(x) group varied with increasing O atoms and Si/O atomic ratios.Experimentally,SiO and SiO_(2) passivation films were fabricated by electron beam evaporation on a Ge substrate,and the valence state of Si and resistivity was measured to characterize the film.The minority carrier lifetime of Ge-SiO_(2) is 21.3 ls,which is approximately quadruple that of Ge-SiO.The passivation effect and mechanism are discussed in terms of hopping conduction and surface defect density.This study builds a relationship between the passivation effect and different termination groups,and provides technical support for the potential passivation layer,which can be applied in Ge detectors with ultralow energy thresholds and especially in HPGe for rare-event physics detection experiments in future.展开更多
AIM: To assess an early termination of immune toler-ance state of chronic hepatitis B virus infection in Ban-gladesh and its clinical significance. METHODS: From a series of 167 treatment-naive chronic hepatitis B pat...AIM: To assess an early termination of immune toler-ance state of chronic hepatitis B virus infection in Ban-gladesh and its clinical significance. METHODS: From a series of 167 treatment-naive chronic hepatitis B patients aged between 12 to 20 years(mean ± SD; 17.5 ± 2.8 years), percutaneous liver biopsies of 89 patients who were all hepatitis B e antigen negative at presentation were done. Of them, 81 were included in the study. They had persistently normal or raised serum alanine aminotransferase(ALT) values. A precore mutation(PCM) study was accom-plished in 8 patients who were randomly selected. RESULTS: Forty-four(53.7%) patients had significant necroinflammation(HAI-NI > 7), while significant fi-brosis(HAI-F ≥ 3) was seen in 15(18.5%) patients. Serum ALT(cut off 42 U/L) was raised in 29(35.8%) patients, while low HBV DNA load(< 105 copies/mL)was observed in 57(70.4%) patients. PCM was nega-tive in all 8 patients. CONCLUSION: This study indicates that the current concept of age-related immune tolerance state of HBV infection deserves further analyses in different popula-tion groups.展开更多
The planar edge termination techniques of junction termination extension (JTE) and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional de...The planar edge termination techniques of junction termination extension (JTE) and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional device simulator ISE-TCAD10.0. By experimental verification, a good consistency between simulation and experiment can be observed. The results show that the reverse breakdown voltage for the 4H-SiC P-i-N diode with optimized JTE edge termination can accomplish near ideal breakdown voltage and much lower leakage current. The breakdown voltage can be near 1650 V, which achieves more than 90 percent of ideal parallel plane junction breakdown voltage and the leakage current density can be near 3 ×10^-5 A/cm2.展开更多
We investigate the behavior of edge modes in the presence of different edge terminations and long-range(LR)hopping.Here,we mainly focus on such model crystals with two different types of structures(type I:“…-P-Q-P-Q...We investigate the behavior of edge modes in the presence of different edge terminations and long-range(LR)hopping.Here,we mainly focus on such model crystals with two different types of structures(type I:“…-P-Q-P-Q-…”and type II:“…=P-Q=P-Q=…”),where P and Q represent crystal lines(CLs),while the symbols“-”and“=”denote the distance between the nearest neighbor(NN)CLs.Based on the lattice model Hamiltonian with LR hopping,the existence of edge modes is determined analytically by using the transfer matrix method(TMM)when different edge terminals are taken into consideration.Our findings are consistent with the numerical results obtained by the exact diagonalization method.We also notice that edge modes can exhibit different behaviors under different edge terminals.Our result is helpful in solving novel edge modes in honeycomb crystalline graphene and transition metal dichalcogenides with different edge terminals.展开更多
The vertical GaN-on-GaN Schottky barrier diode with boron-implanted termination was fabricated and characterized.Compared with the Schottky barrier diode(SBD)without boron-implanted termination,this SBD effectively im...The vertical GaN-on-GaN Schottky barrier diode with boron-implanted termination was fabricated and characterized.Compared with the Schottky barrier diode(SBD)without boron-implanted termination,this SBD effectively improved the breakdown voltage from 189 V to 585 V and significantly reduced the reverse leakage current by 10^5 times.In addition,a high Ion/Ioff ratio of ~10^8 was achieved by the boron-implanted technology.We used Technology Computer Aided Design(TCAD)to analyze reasons for the improved performance of the SBD with boron-implanted termination.The improved performance of diodes may be attributed to that B+could confine free carriers to suppress electron field crowding at the edge of the diode,which could improve the breakdown voltage and suppress the reverse leakage current.展开更多
Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been ...Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been notable variations of studies around it. This paper analyzes the impact of privatization on terminal efficiency using the Port of Tema as a Case Study. The main objective of this paper is to analyze the efficiency trends of the public and private terminals in the port over the years. To achieve this objective, DEA-CCR methodology was employed to calculate the annual technical efficiency trends of the private and public terminals using four input variables and three output variables. The main results of the paper indicated that the public and private terminals were efficient for multiple years. However, the efficiency scores over the years demonstrated inconsistency, exhibiting notable fluctuations. The findings of this study will aid policymakers across the region on policies relating to the efficiency and ownership structure of ports and terminals.展开更多
Improving the cooperative scheduling efficiency of equipment is the key for automated container terminals to copewith the development trend of large-scale ships. In order to improve the solution efficiency of the exis...Improving the cooperative scheduling efficiency of equipment is the key for automated container terminals to copewith the development trend of large-scale ships. In order to improve the solution efficiency of the existing spacetimenetwork (STN) model for the cooperative scheduling problem of yard cranes (YCs) and automated guidedvehicles (AGVs) and extend its application scenarios, two improved STN models are proposed. The flow balanceconstraints in the original model are decomposed, and the trajectory constraints of YCs and AGVs are added toacquire the model STN_A. The coupling constraint in STN_A is updated, and buffer constraints are added toSTN_A so that themodel STN_B is built.As the size of the problem increases, the solution speed of CPLEX becomesthe bottleneck. So a heuristic method containing three groups of heuristic rules is designed to obtain a near-optimalsolution quickly. Experimental results showthat the computation time of STN_A is shortened by 49.47% on averageand the gap is reduced by 1.69% on average compared with the original model. The gap between the solution ofthe heuristic rules and the solution of CPLEX is less than 3.50%, and the solution time of the heuristic rules is onaverage 99.85% less than the solution time of CPLEX. Compared with STN_A, the computation time for solvingSTN_B increases by 58.93% on average.展开更多
The low efficiency and high cost of fresh agricultural product terminal distribution directly restrict the operation of the entire supply network.To reduce costs and optimize the distribution network,we construct a mi...The low efficiency and high cost of fresh agricultural product terminal distribution directly restrict the operation of the entire supply network.To reduce costs and optimize the distribution network,we construct a mixed integer programmingmodel that comprehensively considers tominimize fixed,transportation,fresh-keeping,time,carbon emissions,and performance incentive costs.We analyzed the performance of traditional rider distribution and robot distribution modes in detail.In addition,the uncertainty of the actual market demand poses a huge threat to the stability of the terminal distribution network.In order to resist uncertain interference,we further extend the model to a robust counterpart form.The results of the simulation show that the instability of random parameters will lead to an increase in the cost.Compared with the traditional rider distribution mode,the robot distribution mode can save 12.7%on logistics costs,and the distribution efficiency is higher.Our research can provide support for the design of planning schemes for transportation enterprise managers.展开更多
Background: Perforations of the terminal ileum are a frequent clinical situation and a therapeutic challenge. Surgical treatment is controversial. Several surgical modalities have been proposed and postoperative morbi...Background: Perforations of the terminal ileum are a frequent clinical situation and a therapeutic challenge. Surgical treatment is controversial. Several surgical modalities have been proposed and postoperative morbidity and mortality remain high. The aim of this study was to review our experience in the surgical management of perforations of the terminal ileum. Patients and methods: This is a descriptive cross-sectional study with retrospective data collection from January 1, 2017 to December 31, 2021, in five hospitals in Cameroon. Patients’ demographic, clinical presentation, surgical findings and 30-days postoperative outcomes data were collected. Results: We collected 34 files. The sex ratio was 1.4 and the average age was 20.28 years. The average consultation time was 9.1 days. Abdominal pain was present in all our patients. Peritoneal irritation was present in 46 cases (88.5%). The mean time to treatment after admission was 17.5 hours. The perforation was unique in 40 cases (76.9%) and located between 6 and 10 cm from the ileocecal valve in 29 cases (55.8%). Typhoid was the most suspected etiology intraoperatively in 38 cases (73.1%). A simple suture was performed in 18 patients (34.6%), resection with anastomosis in 11 patients (21.2%) and an ileostomy in 5 patients (9.6%). The average length of hospitalization was 21.74 days. Postoperative morbidity and mortality were 32.7% and 17.3% respectively. Conclusion: Perforations of the terminal ileum are common and affect young people. Surgical procedures are varied. Reducing consultation and care times and respecting treatment principles could improve postoperative morbidity and mortality, which remain high.展开更多
By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier curve and rational Bézier curve. And the termination criterion for subdivision of t...By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier curve and rational Bézier curve. And the termination criterion for subdivision of the rational Bézier curve is also improved. The conclusion of the extreme value problem is thus further confirmed.展开更多
Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage (Fig. 1 ) or Central Asian Orogenic Belt (CAOB), which separate the East European and...Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage (Fig. 1 ) or Central Asian Orogenic Belt (CAOB), which separate the East European and Siberian cratons to the north from the Tarim and North China cratons to the south ($eng0r et al,, 1993; Jahn et al., 2004; Windley et al., 2007; Qu et al., 2008; Xiao et al., 2010; Xiao and Santosh, 2014). The Altaid Collage was characterized by complex long tectonic and structural evolution from at least ca. 1.0 Ga to late Paleozoic-early Mesozoic with considerable continental growth (Khain et al., 2002; Jahn et al., 2004; Xiao et al., 2009, 2014; KrOner et al., 2014), followed by Cenozoic intracontinental evolution related to far-field effect of the collision of the In- dian Plate to the Eurasian Accompanying with these complex world-class ore deposits developed 2001; Goldfarb et al., 2003, 2014). Plate (Cunningham, 2005). geodynamic evolutions, many (Qin, 2000; Yakubchuk et al,2001; Goldfarb et al., 2003, 2014).展开更多
基金supported by the Department of Defense AFIRMⅢW81XWH-20-2-0029 grant subcontractLone Star Paralysis gift,UT POC19-1774-13 grant+1 种基金Neuraptive Therapeutics Inc.26-7724-56 grantNational Institutes of Health R01-NS128086(all to GDB)。
文摘Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.
基金jointly supported by the Open Fund of State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Developmentthe Natural Science Foundation of Sichuan Province(Grant No.24NSFSC4125)。
文摘1.Objective The Emeishan basalts is located in southwest China and northern Vietnam,covering an area of 2.5×10^(5) km^(2)(Zhong YT et al.,2014),which is the first widely recognized large igneous province(LIP)in China(Zhang ZS,2009).The Emeishan LIP has attracted a numbers of scholars for the reason that the LIP may play a significant role in the evolution of environment and climate.Yang JH et al.,(2018)pointed out that the weathering of the Emeishan basalts consumed carbon dioxide and caused a decrease in the climate of the early Wuchiapingian.However,the duration and termination of the Emeishan basalts eruption remain in doubt.This paper reports a new discovery of tuffaceous in the middle part of the Upper Permian Wujiaping Formation from the northern margin of the Sichuan Basin,applying of LA-ICP-MS to obtain zircon U-Pb ages of tuffaceous and to constrain the lasted eruption timing of Emeishan LIP.
文摘Background: Termination of pregnancy (TOP) in Zambia is guided by the Termination of Pregnancy (TOP) Act of 1972 and as amended in 1994 of the laws of Zambia. However, despite provision of Comprehensive abortion care services with the liberal law, statistics at Kanyama First Level Hospital in relation to unsafe illegal abortions are alarming. This study sought to understand the Awareness on the TOP Act of the laws of Zambia among women of reproductive age 15 - 49 years at Kanyama First Level Hospital in Lusaka District. Purpose of the Study: To assess awareness on the TOP Act among women of reproductive age at Kanyama First Level Hospital in Lusaka, Zambia. Methodology: A convergent parallel mixed method design was conducted using both survey and in-depth interviews among women of reproductive age at Kanyama First Level Hospital in Lusaka District. The study surveyed 370 randomly sampled women aged 15 to 49 years old while the in-depth interviews included eight women purposively sampled from the survey population. Survey data was analyzed using descriptive and inferential statistics while qualitative data thematic analysis was used. Results: The study found that 37% of the participants were aware of the TOP Act while 63.8% viewed legalization of abortion for any reason as wrong. The study results also showed that widowed women were 8 times more likely to be aware of the TOP Act compared to single women (AOR: 8.262;95% CI: 1.105, 61.778). Women in business were significantly more likely to be aware of the TOP Act compared to those who reported having no occupation. (AOR: 2.61;95% CI: 1.246, 5.499). Limited access to information, the social stigma attached to abortion, health care providers’ attitudes, cultural norms, values and religious beliefs, restrictive legal requirements, and absence of a supportive network were some of the barriers affecting awareness and utilization of available safe abortion care services. Conclusions: The research findings concluded that a significant lack of awareness among women of reproductive age regarding the Termination of Pregnancy (TOP) Act. The majority of respondents held the view that abortion should only be legalized for medical reasons. Furthermore, there was a notable gap in knowledge concerning the penal code’s provisions on abortion.
文摘The present study, carried out in the forest (Daloa) and pre-forest (M’Bahiakro) zones of Cote d’Ivoire, aims to determine soil landscape units using the coding method. Geological maps and satellite images (SRTM and Landsat) were used for this purpose. The methodological approach adopted consisted in producing maps of slope, geology, land use and topography using the codification method. These various maps, integrated into a GIS using the coding aggregation method, were used to generate soil landscape maps. Twenty-seven (27) soil landscapes have been identified for the pre-forest zone (M’Bahiakro), with a strong dominance of acid rock over a moderate relief under savannah, forest/degraded forest and crops/fallow. However, the forest zone (Daloa), with forty-one (41) soil landscapes identified over the entire zone, is characterized by a majority of mafic rocks on a medium altitude under forest/degraded forest, water and crops/fallow. The criteria used from the codification method (sum of aggregations) made it possible to predict the spatial distribution of soil map units according to agro-ecological environments in the humid intertropical zone. This is essential for the orientation and reinforcement of soil survey tools. However, a comparative evaluation of the different multicriteria analysis methods for coding and weighting soil landscape unit mapping would enable us to identify the most suitable and efficient method for drawing up base maps for soil surveys.
基金This study was supported by a grant from the National Natural Science Foundation of China(81870457).
文摘Background:Acute suppurative terminal cholangitis(ASTC)is rarer than acute obstructive cholangitis and is not well studied.To explore this subtype of acute cholangitis,we described our clinical experience with ASTC.Methods:We performed a retrospective review of patients with ASTC admitted to our center from September 2014 to August 2020.We analyzed their clinical characteristics,including etiology,clinical manifestations,imaging features,treatment and prognosis.Results:A total of 32 ASTC patients were included in the analysis.The majority of the patients had a history of biliary operations,and clinical manifestations were occult and atypical.The positive rate of bacterial culture was 46.9%.All the patients had typical imaging features on computed tomography and magnetic resonance imaging.Treatment with effective antibiotics was provided as soon as diagnosis was established.After treatment,most patients had a good outcome.Elevated levels of total bilirubin,aspartate aminotransferase,procalcitonin and gamma-glutamyltransferase were the characteristics of critically ill patients and were associated with relatively poor prognosis.Conclusions:Our results demonstrated that ASTC should be recognized as a new subtype of acute cholangitis,and that earlier diagnosis and more personalized treatments are needed.
文摘Machine learning(ML) is well suited for the prediction of high-complexity,high-dimensional problems such as those encountered in terminal ballistics.We evaluate the performance of four popular ML-based regression models,extreme gradient boosting(XGBoost),artificial neural network(ANN),support vector regression(SVR),and Gaussian process regression(GP),on two common terminal ballistics’ problems:(a)predicting the V50ballistic limit of monolithic metallic armour impacted by small and medium calibre projectiles and fragments,and(b) predicting the depth to which a projectile will penetrate a target of semi-infinite thickness.To achieve this we utilise two datasets,each consisting of approximately 1000samples,collated from public release sources.We demonstrate that all four model types provide similarly excellent agreement when interpolating within the training data and diverge when extrapolating outside this range.Although extrapolation is not advisable for ML-based regression models,for applications such as lethality/survivability analysis,such capability is required.To circumvent this,we implement expert knowledge and physics-based models via enforced monotonicity,as a Gaussian prior mean,and through a modified loss function.The physics-informed models demonstrate improved performance over both classical physics-based models and the basic ML regression models,providing an ability to accurately fit experimental data when it is available and then revert to the physics-based model when not.The resulting models demonstrate high levels of predictive accuracy over a very wide range of projectile types,target materials and thicknesses,and impact conditions significantly more diverse than that achievable from any existing analytical approach.Compared with numerical analysis tools such as finite element solvers the ML models run orders of magnitude faster.We provide some general guidelines throughout for the development,application,and reporting of ML models in terminal ballistics problems.
基金Project supported by the Research Fund of Low Cost Fabrication of GaN Power Devices and System Integration,China(Grant No.JCYJ20160226192639004)the Research Fund of AlGaN HEMT MEMS Sensor for Work in Extreme Environment,China(Grant No.JCYJ20170412153356899)the Research Fund of Reliability Mechanism and Circuit Simulation of GaN HEMT,China(Grant No.2017A050506002)
文摘In this work, the field plate termination is studied for Ga2O3Schottky barrier diodes(SBDs) by simulation. The influence of field plate overlap, dielectric material and thickness on the termination electric field distribution are demonstrated.It is found that the optimal thickness increases with reverse bias increasing for all the three dielectrics of SiO2, Al2O3, and HfO2. As the thickness increases, the maximum electric field intensity decreases in SiO2and Al2O3, but increases in HfO2.Furthermore, it is found that SiO2and HfO2are suitable for the 600 V rate Ga2O3SBD, and Al2O3is suitable for both600 V and 1200 V rate Ga2O3SBD. In addition, the comparison of Ga2O3SBDs between the SiC and GaN counterpart reveals that for Ga2O3, the breakdown voltage bottleneck is the dielectric. While, for SiC and GaN, the bottleneck is mainly the semiconductor itself.
基金supported by the National Natural Science Foundation of China Youth Fund(No.12005017)。
文摘The point-contact high-purity germanium detector(HPGe)has the advantages of low background,low energy threshold,and high energy resolution and can be applied in the detection of rare-event physics.However,the performance of HPGe must be further improved to achieve superior energy resolution,low noise,and long-term reliability.In this study,we combine computational simulations and experimental comparisons to deeply understand the passivation mechanism of Ge.The surface passivation effect is calculated and inferred from the band structure and density of interface states,and further con-firmed by the minority carrier lifetime.The first-principles method based on the density functional theory was adopted to systematically study the lattice structure,band structure,and density of state(DOS)of four different systems:Ge–H,Ge–Ge-NH 2,Ge-OH,and Ge-SiO_(x).The electronic char-acteristics of the Ge(100)unit cell with different passi-vation groups and Si/O atomic ratios were compared.This shows that H,N,and O atoms can effectively reduce the surface DOS of the Ge atoms.The passivation effect of the SiO_(x) group varied with increasing O atoms and Si/O atomic ratios.Experimentally,SiO and SiO_(2) passivation films were fabricated by electron beam evaporation on a Ge substrate,and the valence state of Si and resistivity was measured to characterize the film.The minority carrier lifetime of Ge-SiO_(2) is 21.3 ls,which is approximately quadruple that of Ge-SiO.The passivation effect and mechanism are discussed in terms of hopping conduction and surface defect density.This study builds a relationship between the passivation effect and different termination groups,and provides technical support for the potential passivation layer,which can be applied in Ge detectors with ultralow energy thresholds and especially in HPGe for rare-event physics detection experiments in future.
文摘AIM: To assess an early termination of immune toler-ance state of chronic hepatitis B virus infection in Ban-gladesh and its clinical significance. METHODS: From a series of 167 treatment-naive chronic hepatitis B patients aged between 12 to 20 years(mean ± SD; 17.5 ± 2.8 years), percutaneous liver biopsies of 89 patients who were all hepatitis B e antigen negative at presentation were done. Of them, 81 were included in the study. They had persistently normal or raised serum alanine aminotransferase(ALT) values. A precore mutation(PCM) study was accom-plished in 8 patients who were randomly selected. RESULTS: Forty-four(53.7%) patients had significant necroinflammation(HAI-NI > 7), while significant fi-brosis(HAI-F ≥ 3) was seen in 15(18.5%) patients. Serum ALT(cut off 42 U/L) was raised in 29(35.8%) patients, while low HBV DNA load(< 105 copies/mL)was observed in 57(70.4%) patients. PCM was nega-tive in all 8 patients. CONCLUSION: This study indicates that the current concept of age-related immune tolerance state of HBV infection deserves further analyses in different popula-tion groups.
基金Project supported by the Science and Technology Foundation of Hunan Province of China (Grant No. 2008FJ3102)
文摘The planar edge termination techniques of junction termination extension (JTE) and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional device simulator ISE-TCAD10.0. By experimental verification, a good consistency between simulation and experiment can be observed. The results show that the reverse breakdown voltage for the 4H-SiC P-i-N diode with optimized JTE edge termination can accomplish near ideal breakdown voltage and much lower leakage current. The breakdown voltage can be near 1650 V, which achieves more than 90 percent of ideal parallel plane junction breakdown voltage and the leakage current density can be near 3 ×10^-5 A/cm2.
基金supported by the National Natural Science Foundation of China(Grant No.11847061)Domestic Visiting Program for Young and Middle-aged Teachers in Shanghai Universities.
文摘We investigate the behavior of edge modes in the presence of different edge terminations and long-range(LR)hopping.Here,we mainly focus on such model crystals with two different types of structures(type I:“…-P-Q-P-Q-…”and type II:“…=P-Q=P-Q=…”),where P and Q represent crystal lines(CLs),while the symbols“-”and“=”denote the distance between the nearest neighbor(NN)CLs.Based on the lattice model Hamiltonian with LR hopping,the existence of edge modes is determined analytically by using the transfer matrix method(TMM)when different edge terminals are taken into consideration.Our findings are consistent with the numerical results obtained by the exact diagonalization method.We also notice that edge modes can exhibit different behaviors under different edge terminals.Our result is helpful in solving novel edge modes in honeycomb crystalline graphene and transition metal dichalcogenides with different edge terminals.
基金Project supported by the National Key R&D Program of China(Grant No.2017YFB0404100)Science and Technology Planning Project of Guangdong Province,China(Grant No.2017B010112001)。
文摘The vertical GaN-on-GaN Schottky barrier diode with boron-implanted termination was fabricated and characterized.Compared with the Schottky barrier diode(SBD)without boron-implanted termination,this SBD effectively improved the breakdown voltage from 189 V to 585 V and significantly reduced the reverse leakage current by 10^5 times.In addition,a high Ion/Ioff ratio of ~10^8 was achieved by the boron-implanted technology.We used Technology Computer Aided Design(TCAD)to analyze reasons for the improved performance of the SBD with boron-implanted termination.The improved performance of diodes may be attributed to that B+could confine free carriers to suppress electron field crowding at the edge of the diode,which could improve the breakdown voltage and suppress the reverse leakage current.
文摘Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been notable variations of studies around it. This paper analyzes the impact of privatization on terminal efficiency using the Port of Tema as a Case Study. The main objective of this paper is to analyze the efficiency trends of the public and private terminals in the port over the years. To achieve this objective, DEA-CCR methodology was employed to calculate the annual technical efficiency trends of the private and public terminals using four input variables and three output variables. The main results of the paper indicated that the public and private terminals were efficient for multiple years. However, the efficiency scores over the years demonstrated inconsistency, exhibiting notable fluctuations. The findings of this study will aid policymakers across the region on policies relating to the efficiency and ownership structure of ports and terminals.
基金National Natural Science Foundation of China(62073212).
文摘Improving the cooperative scheduling efficiency of equipment is the key for automated container terminals to copewith the development trend of large-scale ships. In order to improve the solution efficiency of the existing spacetimenetwork (STN) model for the cooperative scheduling problem of yard cranes (YCs) and automated guidedvehicles (AGVs) and extend its application scenarios, two improved STN models are proposed. The flow balanceconstraints in the original model are decomposed, and the trajectory constraints of YCs and AGVs are added toacquire the model STN_A. The coupling constraint in STN_A is updated, and buffer constraints are added toSTN_A so that themodel STN_B is built.As the size of the problem increases, the solution speed of CPLEX becomesthe bottleneck. So a heuristic method containing three groups of heuristic rules is designed to obtain a near-optimalsolution quickly. Experimental results showthat the computation time of STN_A is shortened by 49.47% on averageand the gap is reduced by 1.69% on average compared with the original model. The gap between the solution ofthe heuristic rules and the solution of CPLEX is less than 3.50%, and the solution time of the heuristic rules is onaverage 99.85% less than the solution time of CPLEX. Compared with STN_A, the computation time for solvingSTN_B increases by 58.93% on average.
文摘The low efficiency and high cost of fresh agricultural product terminal distribution directly restrict the operation of the entire supply network.To reduce costs and optimize the distribution network,we construct a mixed integer programmingmodel that comprehensively considers tominimize fixed,transportation,fresh-keeping,time,carbon emissions,and performance incentive costs.We analyzed the performance of traditional rider distribution and robot distribution modes in detail.In addition,the uncertainty of the actual market demand poses a huge threat to the stability of the terminal distribution network.In order to resist uncertain interference,we further extend the model to a robust counterpart form.The results of the simulation show that the instability of random parameters will lead to an increase in the cost.Compared with the traditional rider distribution mode,the robot distribution mode can save 12.7%on logistics costs,and the distribution efficiency is higher.Our research can provide support for the design of planning schemes for transportation enterprise managers.
文摘Background: Perforations of the terminal ileum are a frequent clinical situation and a therapeutic challenge. Surgical treatment is controversial. Several surgical modalities have been proposed and postoperative morbidity and mortality remain high. The aim of this study was to review our experience in the surgical management of perforations of the terminal ileum. Patients and methods: This is a descriptive cross-sectional study with retrospective data collection from January 1, 2017 to December 31, 2021, in five hospitals in Cameroon. Patients’ demographic, clinical presentation, surgical findings and 30-days postoperative outcomes data were collected. Results: We collected 34 files. The sex ratio was 1.4 and the average age was 20.28 years. The average consultation time was 9.1 days. Abdominal pain was present in all our patients. Peritoneal irritation was present in 46 cases (88.5%). The mean time to treatment after admission was 17.5 hours. The perforation was unique in 40 cases (76.9%) and located between 6 and 10 cm from the ileocecal valve in 29 cases (55.8%). Typhoid was the most suspected etiology intraoperatively in 38 cases (73.1%). A simple suture was performed in 18 patients (34.6%), resection with anastomosis in 11 patients (21.2%) and an ileostomy in 5 patients (9.6%). The average length of hospitalization was 21.74 days. Postoperative morbidity and mortality were 32.7% and 17.3% respectively. Conclusion: Perforations of the terminal ileum are common and affect young people. Surgical procedures are varied. Reducing consultation and care times and respecting treatment principles could improve postoperative morbidity and mortality, which remain high.
文摘By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier curve and rational Bézier curve. And the termination criterion for subdivision of the rational Bézier curve is also improved. The conclusion of the extreme value problem is thus further confirmed.
基金financially supported by the Natural National Science Foundation of China(Grant Nos.41230207,41202150, 41472192,41390441 and 41190075)
文摘Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage (Fig. 1 ) or Central Asian Orogenic Belt (CAOB), which separate the East European and Siberian cratons to the north from the Tarim and North China cratons to the south ($eng0r et al,, 1993; Jahn et al., 2004; Windley et al., 2007; Qu et al., 2008; Xiao et al., 2010; Xiao and Santosh, 2014). The Altaid Collage was characterized by complex long tectonic and structural evolution from at least ca. 1.0 Ga to late Paleozoic-early Mesozoic with considerable continental growth (Khain et al., 2002; Jahn et al., 2004; Xiao et al., 2009, 2014; KrOner et al., 2014), followed by Cenozoic intracontinental evolution related to far-field effect of the collision of the In- dian Plate to the Eurasian Accompanying with these complex world-class ore deposits developed 2001; Goldfarb et al., 2003, 2014). Plate (Cunningham, 2005). geodynamic evolutions, many (Qin, 2000; Yakubchuk et al,2001; Goldfarb et al., 2003, 2014).